A microdevice for the mixing of a highly viscous biosample with water/membrane protein solution using microchannel and centrifugation.

A mechanism for controlling the mixing of highly viscous biosamples at the microliter scale is presented. Existing methods for mixing biosamples using microstirrers or shaking microwells are only effective for non-highly viscous materials. The proposed mechanism mixes monoolein, a highly viscous biosample, with water/membrane protein solution in a microdevice called microcapsule using a microchannel and centrifugation. To achieve effective mixing, the design of the microcapsule along with the microchannel is presented and so is the hydrodynamic model describing the flow of viscous materials in the microchannel. The mixing process is analyzed according to the Reynolds number of the biosamples using computer simulation, which is observed during the experiment using digital images for further analysis. Finally, the new approach is verified by X-ray diffraction experiments with water and the Rh membrane protein solution, which are used to evaluate the effectiveness of mixing. Experimental results not only validate the proposed method but also determine the flow oscillation time in the microchannel to achieve effective and efficient mixing.